The internal combustion engine has provided the heart of self-powered road vehicles by combusting fuel to drive pistons within cylinders such that the movements of the pistons turn a crankshaft that then turns the vehicle wheels via a drive shaft. Due to the dependence upon different types of combustible fuels (e.g., gasoline, Diesel, natural gas, etc.) to power such engines, other technologies have emerged as alternatives to the internal combustion engine. For example, electric vehicles use an electric motor for propulsion rather than being powered by an on-board internal combustion engine. Hybrid-electric vehicles have been developed that combine conventional internal combustion engine propulsion systems with electric propulsion systems. In such hybrid-electric vehicles, powering a drivetrain with an electric motor during at least a portion of a vehicle's drive cycle can achieve better fuel economy and lower emissions relative to a conventional internal combustion engine-powered vehicle, while achieving comparable performance and other positive attributes.